The leukotrienes constitute a group of locally acting hormones, produced in living systems from arachidonic acid. The major leukotrienes are leukotriene B.sub.4 (abbreviated as LTB.sub.4), LTC.sub.4, LTD.sub.4, and LTE.sub.4. The biosynthesis of these leukotrienes begins with the action of the enzyme 5-lipoxygenase on arachidonic acid to produce the epoxide known as Leukotriene A.sub.4 (LTA.sub.4), which is converted to the other leukotrienes by subsequent enzymatic steps. Further details of the biosynthesis as well as the metabolism of the leukotrienes are to be found in the book Leukotrienes and Lipoxygenases, ed. J. Rokach, Elsevier, Amsterdam (1989). The actions of the leukotrienes in living systems and their contribution to various disease states are also discussed in the book by Rokach.
There has been reported in U.S. Pat. No. 5,270,324 a class of quinoline type leukotriene antagonists, of which compounds having the formula (I) are a subset: ##STR1## wherein R.sup.a, R.sup.b are, inter alia, hydrogen or a halogen; and R.sup.c may be CO.sub.2 R.sup.d, COR.sup.d or C(R.sup.e).sub.2 --OH; R.sup.d may be hydrogen or a lower alkyl, and R.sup.e may be lower alkyl; and ALK is for example cyclopropyl-1,1-(bis)methylene, isopropyl, and the like.
There is further disclosed in European Published Application 604114 leukotriene antagonists, of which compounds having the formula (II) are a subset: ##STR2## in which R.sup.a, R.sup.b, R.sup.c and ALK are as given above.
(S)-Hydroxy compounds of formula (IV), infra, are intermediates in the synthesis of compounds of formulae (I) and (II). Compounds of formula (IV) may be prepared from the corresponding ketones of formula (III), infra, by using a chiral reducing agent such as diisopinocampheylchloroborane. The chemical chiral reduction generally requires the use of expensive chiral reducing agents; therefore, there exists a need for an alternative method for the preparation of chiral compounds of formula (IV) that may be more economical and/or more convenient than the chemical method.